8 years of no Batman or Bruce Wayne, and NO ONE could pick up the trend?

I am a fan of Nolan's Batman trilogy, but it was particularly and definitely at its best with TDK and I'm sure I ain't the only one that thinks that. Amongst the complaints I have with the successor, this is one of the biggest complaints I have.

So after 2Face's death, Batman goes in to hiding. At the same time, Bruce Wayne sulks in his palace and doesn't come out. This goes on for 8 years. Then one night, Bruce Wayne cleans up and goes back out into the public. The very next night, Batman returns... but not a single soul in Gotham could put the 2 and 2 together?

That's why I feel the secondary villain for this film, if they were to keep an 8 year Batgap plot like that, would have been the Riddler, instead of having all this focus on the return of LoS. This is similar to BB, where Bruce Wayne returns to Gotham and soon after comes Batman, but the plot unveiled there was more understandable. Here in DKR it is just silly. In my opinion.